a) Field of the Invention
The invention is directed to a loading and unloading station for semiconductor processing installations with at least one closeable charging opening through which wafer-shaped or disk-shaped objects which are accommodated in a transporting container can be loaded, unloaded and reloaded after removing a closure, wherein the transporting container is provided with a container cover which extends substantially at right angles to the loading plane.
b) Description of the Related Art
For the purpose of charging semiconductor processing installations, it is known to use so-called SMIF boxes as magazine containers with a relatively small enclosed volume in which wafer magazines can be stored and transported. The box can be placed on an opening mechanism in an enclosure or housing which encloses one or more work stations so as to keep them free of dust. The box and opening mechanism have closing elements which are adapted to one another and which can be opened simultaneously one above the other so that dust particles resting on the outside of the closing elements can be enclosed therebetween when the wafer magazines are lowered into the housing together with the two closing elements. The box itself encloses the opening formed in the housing.
A loading and unloading device according to the German Patent 43 26 309 C1, for example, or a device having another operating sequence serves to remove the magazines from the transporting containers and place them in the processing installation. After the semiconductor wafers are processed, the magazines are transported back in the transporting containers.
The technique of SMIF boxes is especially suited for semiconductor wafers with smaller diameters, as is conventional. In view of the material characteristics of the semiconductor wafers, these SMIF boxes and the wafer magazines used with them are becoming increasingly unsuitable as transporting containers as the diameter of semiconductor wafers increases. Transporting containers which take over the function of magazines at the same time are already known for semiconductor wafers of this type. Loading, unloading and reloading of the semiconductor wafers is effected individually in a plane parallel to the surface of the semiconductor wafers, wherein the transporting container can be closed by a container cover extending substantially at right angles to the loading and unloading plane. Accordingly, in contrast to the SMIF box, the container cover is removed and inserted laterally rather than in a downward direction.
Since the transporting containers are enclosed by a space with low requirements as regards cleanness and since there are no magazines which can be loaded and unloaded such as those used in the SMIF technique, the charging of semiconductor processing installations proceeding from these transporting containers and the transporting back from such installations into the transporting containers presents problems. Moreover, the problem is exacerbated in that optional loading and unloading into and out of a greater number of transporting containers must be ensured under certain circumstances and the containers themselves must be supplied and removed by operating personnel under favorably ergonomic conditions.
An arrangement for storing, transporting and inserting substrates is known from EP 542 793 B1. In this arrangement, a cassette with a lateral closing cap is arranged opposite a loading slot. The cassettes are brought into the loading position one after the other by a lifting plate which can hold a packet of stacked cassettes. When this position is reached, the closing cap is swiveled open at one edge and the substrate wafer is inserted into the clean room by a drawer which can travel out of the cassette. An air flow exiting from the loading slot prevents particles from penetrating into the clean room in that it passes through an open gap between a protruding seal and the cassette.
The primary object of the present invention is to ensure a charging of semiconductor processing installations proceeding from transporting containers under clean room conditions, these transporting containers themselves serving as magazines for disk-shaped objects and being open laterally. It should also be possible, optionally, to load and unload a greater quantity of such transporting containers, wherein the exchange of transporting containers must be effected under favorable ergonomic conditions.
In a loading and unloading station for semiconductor processing installations with a closable charging opening through which disk-shaped objects, which are accommodated in a transporting container, can be loaded, unloaded and reloaded after removing a closure, wherein the transporting container is provided with a container cover which substantially extends so as to be directed vertically to the loading and unloading plane, the object according to the present invention is met in that the transporting container for loading, unloading and reloading of disk-shaped objects is coupled in a stationary manner by the container cover with the closure by means of an adhering engagement and a simultaneous opening of the charging opening and transporting container is effected in that the container cover and the closure are moved down jointly into the semiconductor processing installation. The loading and unloading is carried out in that a manipulating device which is arranged in the semiconductor processing installation engages through the charging opening into the transporting container.
For the purpose of coupling with the closure, the transporting container is deposited on a horizontally adjustable first platform which is provided with means for aligning and securing the transporting container.
The platform is adjustable between at least two planes which are located one above the other, one of which planes serves for charging with a transporting container at an ergonomic height, while the other serves for loading and unloading the semiconductor processing installation.
In an advantageous manner, a suitable number of additional, horizontally adjustable platforms which are provided with means for aligning and securing the transporting container can be provided for holding at least one additional transporting container. At least one of the platforms serves alternately to couple a transporting container with the closure, while the others remain free for the exchange of transporting containers.
A storage is also advantageously provided for the exchange of transporting containers, in which storage a gripper has optional access to storage compartments or shelves which are arranged one above the other and a loading opening with a transporting container holder is provided for manual charging with transporting containers. A space corresponding to the dimensions of a transporting container is left open adjacent to the storage shelves for transferring the transporting containers between the transporting container holder, storage shelves, and the platform. The transporting container holder should be able to travel out through the loading opening for the purpose of charging.
Further, the closure advantageously has vacuum suction devices for producing the adhering engagement with the container cover and is provided with elements for aligning relative to the container cover which can take effect before the adhering engagement is produced.
In order to open the transporting container, keys for actuating the locking elements in the container cover project out of the closure, matching keyholes for these keys being provided in the container cover, by which the closure and container cover are secured above and beyond the adhering engagement. The aligning elements and the keys can be held in a springing manner vertically to the loading and unloading plane in order to compensate for differences between the approach of the closure and the container cover.
Also, the charging opening is advantageously worked into a plate or shield which is adjustable, relative to the manipulating device, jointly with the coupled transporting container for loading and unloading the disk-shaped objects in a direction vertical to the loading and unloading plane depending on the indexed positions. Accordingly, it is possible to carry out the movement between the different planes as well as the indexing movements by means of an individual elevator.
However, it is also possible to construct the manipulating device for loading and unloading the disk-shaped objects in a direction vertical to the loading and unloading plane depending upon the indexed positions.
By means of the described solution according to the invention, transporting containers of the type described above can be used without negatively affecting the clean room conditions within the semiconductor processing installation to be charged. Semiconductor wafers with dimensions of 300 mm can be manipulated easily. Dust particles located on the container cover during the coupling with the closure are reliably enclosed between the surfaces which are connected in an adhering engagement.
The invention will be explained more fully in the following with reference to the schematic drawings.